What are relationships among aging, disease and mortality? The investigation of this fundamental question is not limited to experimental and clinical studies but could be extended to demographic and epidemiologic research because age patterns of mortality, disability and mortality are expected to reflect underlying processes of senescence and disease development. The main tool for such analyses has been the plot of the death rate (disability rate, prevalence rate, or incidence rate) against age on the regular, semi-log or log-log graph sheets. Results by this "crude" procedure tend to suggest that age patterns of mortality are relatively stable and fitted well to such simple mathematical forms as the Gompertz, Makeham, and Weibull equations. New methodologies are being developed that reflect age and cohort variations in mortality more sensitively than the conventional approach. Preliminary results using the new approach indicate that there are significant differences in age patterns of mortality among major causes of death, over time, between sexes, and among countries. These variations in age-related mortality increase suggest complicated interactions between aging processes and pathological, physiological, genetic, and life-style factors. Further investigation, however, requires strong background in biomedical sciences and applied mathematics as well as substantial experience in quantitative demography. The purpose of this career development program is for the grant recipient (Shiro Horiuchi) to acquire more skills and knowledge in biomedical sciences and applied mathematics and to conduct the proposed study on aging and mortality. Major research issues include: age patterns of mortality for various causes of death; sex differentials, trends and international differences in the speed and acceleration of age-related mortality increase; statistical relationships of these age-variations, trends and differentials with those of risk factors; and biomedical mechanisms underling those patterns, trends, differentials and correlations. These problems will be investigated by (a) analyzing internationally compiled aggregate-level vital and health statistics, (b) analyzing individual-level data from health surveys, (c) linking observed LAR patterns and variations with biomedical theories on aging and disease, and (d) developing mathematical models of relationships among aging, morbidity and mortality based on results of (a), (b) and (c).